Estrogenic steroids regulate FSH production in vivo, but the molecular details are unknown. We propose to investigate these details in a unique in vitro system thereby extending our initial observations on estrogen regulation of FSH biosynthesis in pituitary cell cultures. We would like to characterize the major processes in FSH biosynthesis (messenger RNA production, translation and carbohydrate addition) with initial emphasis on (1) characterization of culture-produced FSH (alpha and beta chain synthesis) and (2) isolation and in vitro translation of FSH mRNA. The effect of estrogens on these processes will be carefully characterized. Further, we will extend our understanding of pituitary function by determining (1) the effects on FSH biosynthesis of estrogens in combination with other steroids, and (2) the effects of various compounds (anti- or pro-gonadotrophic) on FSH biosynthesis in the culture. Our ultimate goal is to understand FSH biosynthesis and release well enough to determine the specific steps influenced by estrogens and, ultimately, to be able to regulate FSH production in vivo.